Dental articulator



Sept. 21, 1965 K. H. SWANSON DENTAL ARTICULATOR N R u 4 @m w 2 N N h w rl N cllbcczgy I S I e U W m H Re. i.

Filed Dec. 17, 1962 wmti ATTORNEYS Sept- 1965 K. H. SWANSON 3,206,852

DENTAL ARTICULATOR Filed Dec. 17, 1962 2 Sheets-Sheet 2 KENNETH H.SWANSON INVENTOR.

ATTORNEYS United States Patent 3,206,852 DENTAL ARTICULATOR Kenneth H.Swanson, 540 North Central Bldg, Glendale, Calif. Filed Dec. 17, 1962,Ser. No. 245,276 6 Claims. (Cl. 32-32) This invention relates to adental articulator for reproducing the relative movements of anindividual persons jaws and, in particular, is directed to such a dentalarticulator for simulating the actual configuration of that personshinge joints between the lower and the upper jaw such that the relativemovement therebetween is closely reproduced.

There are numerous types of dental articulators and various recommendedprocedures to follow in using dental articulators. One importantfunction of every dental articulator is to simulate the relativemovement between the upper and lower jaws to thereby assist the dentistin constructing dentures, bridges, etc. that will have the properspacing, clearance, meshing relation, etc. for comfortable and effectiveuse by the person. As is well known in the art, the joint between thelower jaw and the skull is not a plain hinge joint nor is it a pair ofsimple and uniformly shaped ball and socket joints, but rather the jointis similar to ball and socket joints where the socket is of an irregularshape and the ball is permitted to move longitudinally within the socketas well as pivoting therein. Moreover, it is well known that the shapeof the socket and its orientation relative to the jaws is somewhatdifferent for each person and the configuration and orientation are notreadily ascertainable by observing, X-raying, or testing the particularindividual.

These conventional articulators have many different types of hingemechanisms for attempting to reproduce the pivoting motion of the lowerjaw relative to the skull. Some articulators employ a plain hingebetween two frame members thereby producing a simple pivoting movementthat is unlike the movement of a human jaw which is free to move forwardand back, and laterally as well as pivoting. Other dental articulatorshave used hinge mechanisms employing a pair of spaced pins or ballsmovable within slots of limited lengths and these slots may beadjustable to appropriately orient their lengths relative to theposition of the teeth to more closely simulate the orientation of thatpersons socket relative to their teeth. Although this pin and slotarrangement permits forward and back movement and possibly lateralmovement as well as pivoting movement, these movements can only be mereapproximations of the actual movements of that persons jaw since thehuman joint is not in the form of a straight slot and pin. Some otherarticulators employ a hinge mechanism resembling the human joint withcooperating parts shaped like the irregular human ball and socket.However, the irregular sockets and balls of this type of articulator aremerely constructed to a shape that represents the average shape of thesecomponents in various individuals and does not truly represent theconfiguration or orientation of the ball and socket of any particularindividual. Since the shape and orientation of this hinge in this typeof articulator is merely an average it may be substantially differentthan that of a particular individual and thus does not serve theintended function.

While there have been various conventional methods and procedurespracticed by dentists for measuring some of the charactreistics of thejaw hinge joint and movement of the lower jaw of an individual, some ofthese methods and procedures are useless for adjusting certain types ofdental articulators due to the limited types of adjustments possible.Moreover, when adjustments can be made only an approximation of theactual characteristics of the joint and movement is achieved due to thelimitations on the range and extent of adjustments. Further, thecloseness of the approximation that is made depends on the particularskill, experience, patience and other abilities of the individualdentist as well as being limited by the physical limitations of thedental articulator. Thus, the reproduction of the jaw movements of aparticular individual on a dental articulator might well depend as muchon the ability of the dentist as the physical limitations of thatarticulator.

Although it might well be possible for a particular dentist to performnumerous tests, procedures, X-raying, etc. and then nearly accuratelyreproduce an individuals jaw hinge joint by, for example, carving thejoint components out of a suitable material, such a method would beextremely expensive and time consuming. Again, the quality of resultswould depend on the ability of the individual dentist.

Accordingly, it is a principal object of this invention to provide anovel form of dental articulator and method for using same whereby themovements of a particular individuals jaw may be reproduced bysimulating the actual construction of that individuals joints betweenthe lower jaw and the skull.

Another object of this invention is to provide .a novel form of dentalarticulator that employs .a formable material shaped to simulate theparticular configuration of the sockets of an individual persons balland socket joints between the upper and lower jaws.

A further object of this invention is to provide a dental articulatorwhich is usable for reproducing the relative movement of a particularindivi-duals jaws by recording such movement and causing the articulatorto follow such movement for in turn causing a formable material to beappropriately arranged to simulate the actual configuration of thatindividual persons joint between the lower jaw and the skull.

A still further object of this invention is to provide a novel form ofdental articulator and method for using and adjusting same whereby thedental articulator may be appropriately adjusted to simulate the actuallateral distance between the ball and socket type joints connecting thelower jaw to the skull of a particular individual and wherein theconfiguration of those ball and socket joints may be simulated in anunrestricted fashion by appropriately forming a formable material into asocket shaped con-figuration; the steps of such method of using thearticulator being relatively simple to perform and well within theabilities of at least most dentists. Still another object of thisinvenion is to provide such a method which may be readily used wit-h aminimum of instruction and practice beyond the normal knowledge ofprocedures and method used by dentists.

Still a further object of this invention is to provide a novel form :ofdental articulator that is relatively in expensive, relatively easy touse, .and requires a very minimum of additional devices or materials forits use.

Other and more detailed objects and advantages of this invention willappear from the following description and the accompanying drawings.

In the drawings:

FIGURE 1 is an elevation view of a face bow being used on a patent todetermine certain measurements and relationships for use in adjusting adental articulator of this invention.

FIGURE 2 is a perspective view of the dental articulator of thisinvention together with the face bow shown in FIGURE 1 and illustratingone of the first steps in using the dental articulator.

FIGURE 3 is a perspective view of the dental articulator in an invertedposition from that shown in FIGURE 2 and showing another step in usingthe dental articulator.

FIGURE 4 is an elevation view of the dental articulator illustrating thefinal condition thereof after completion of the steps and adjustmentsneeded such that the articulator is ready for use in constructing thedesired dentures, bridges, etc.

FIGURE 5 is an exploded view of a pair of upper and lower plates used inthe persons upper and lower jaws and in the dental articulator foraccomplishing certain portions of the adjustment of the dentalarticulator.

FIGURE 6 is a perspective view of one of the open boxes used on thearticulator and containing a material appropriately formed to the shapeof a socket.

FIGURE 7 is a sectional elevation of the box and material shown inFIGURE 6 with a die being made of the shape of the formed material shownin FIGURE 6.

FIGURE 8 is an exploded view illustrating the die formed in FIGURE 7being inserted into a material in an open box to reproduce a hard setconfiguration identical to that shown in FIGURE 6 as formed in theformable material.

Referring now in particular to FIGURE 1, a procedu re and apparatus isused which is relatively conventional for determining the hinge axis forthe jaw of the particular person. A conventional face bow, generallydesignated 10, is appropriately mounted and supported in a persons mouthby support rod 11 supporting the lateral rod 12 and a pair of extensionrods 13 are adjustably mounted on lateral rod 12. A pointer 14 isadjustably mounted near the end of extension rod 13 and by having theperson appropriately move his lower jaw the extension rods 13 andpointers 14 may be adjusted so that the pointers 14 are aligned with thehinge axis of the joint between the lower jaw and the skull in the mostretruded position. This location is known as either the centric positionor, perhaps more accurately, as the terminal hinge position of thejoint. A pointer rod 15 is adjustably mounted on lateral rod 12 forpositioning at a particular location on or near the nose of the personso that the particular setting of the face bow and the relationship withthe persons mouth may be subsequently reproduced for various knownpurposes. Thus, by using face bow or other similar devices, theparticular location and spatial relation of the hinge axis of thatperson with respect to that persons mouth may be determined and thensimulated at a location apart from the person. It is to be noted thatthe pointers 14 are adjusted to contact the skin so that the lateralwidth of that persons jaw at the hinge axis is also determined.

Appropriate cast models 16 and 17 are made of the upper and lower jaws,respectively, of the person. These models 16 and 17 may be made in anyconventional manner with conventional materials and may be preparedbefore or after the heretofore described use of the face bow 10 todetermine the hinge axis mounting.

The face bow 10 is then mounted on a support post 18 of a support table19. The dental articulator, generally designated 20, of this inventionis then appropriately positioned on the table 19 in proper orientationwith respect to the face bow 10.

The dental articulator 20 is generally comprised of an upper frame 21and a lower frame 22 which may be of any convenient configuration suchas the T-shape shown. The lower frame 22 may be provided with threeadjustable support legs 23 for appropriately supporting and levellingthe lower frame on table 19 to accomplish the desired alignment with theface bow 10. Similarly, the upper frame 21 may be provided with threesupport legs 24 for permitting the articulator 20 to be completelyinverted and supported by these legs or for supporting frame 21 alonewhen that frame is removed and inverted as desired.

A pair of condyle posts 25 are movably mounted on the lower frame 22 inspaced relation. The condyle posts 25 are adjustably and movably mountedby any convenient means such as a threaded extension 26 on one end ofeach post extending through one of a pair of slots 27 provided in lowerframe 22. The two slots 27 are laterally spaced and aligned with respectto each other. Wing nuts 28 are provided on threaded extensions 26 tosecure the condyle posts 25 to frame 22 and permit ready adjustment ofthe condyle posts toward and away from each other within slots 27. Theextending end of each condyle post 25, opposite the threaded extension26, is provided with a relatively spherical condyle 29. Condyle heads ofvarious shapes like those of human mandibles could be provided. Each ofthe condyles 29 is provided with a pin 30 extending outwardly in anopposite direction from the other condyle and approximately aligned withthe center of the spherical condyle to which it is attached.

The condyle posts 25 are then adjusted laterally to the appropriateposition by positioning frame 22 on table 19 and aligning the pointer 14of the face how 10 with the pins 30. The pins 30 are of an appropriatelength such that the center of the spherical condyles 29 are spaced anappropriate distance from the pointers 14 to correspond approximately tothe distance between the individuals skin and the center of his ball andsocket joint on each side. When the condyle posts 25 are properlypositioned, the wing nuts 28 may be tightened. The frame 22 may beprovided with calibrations 31 along the slots 27 and the post 25 may beprovided with a mark 32 so that the two condyle posts 25 may be centeredwith respect to the frame 22 and also their positions may be recordedand subsequently located for additional use of the articulator.

The frame 21 is provided with an angle guide 33 mounted on the oppositeside of the frame as the legs 24. Guide 33 is positioned at an angle tothe plane of frame 21 and this angle approximates the minimum anglebetween a horizontal plane and the plane of the human socket and balljoint. A pair of three sided open boxes 34 are adjustably mounted in theguide 33 with two of the sides of the box coplanar with the two legs ofthe angle guide 33 and the third side perpendicular to both of the othertwo sides of the box 34. It is to be noted that it is not essential tothis invention that boxes 34 have three mutually perpendicular sides andthat various shapes will be satisfactory. Each of the boxes 34 areadjustably mounted on guide 33 by any convenient means such as athreaded stud 35 extending through a slot 36 in the back leg of theguide 33 with a wing nut 37 for securing the open box 34 in theappropriate location. After the condyle posts 25 have been laterallyadjusted as heretofore described, the upper frame 21 is set on top ofthe lower frame 22 with each of the open boxes 34 resting on top of acondyle 29. Each of the open boxes 34 are moved outwardly with wing nuts37 loosened until each of the spherical condyles 29 engages all threesides of each open box 34, i.e., when the spherical condyle 29 ispositioned in the corner of the three sided open box 34. The wing nuts37 are then tightened. Calibrations may be provided adjacent slot 36similar to calibrations 31 to permit lateral centering of the boxes 34with respect to frame 21 and recording for subsequent relocation of theboxes. With the condyle post 25 and open boxes 34 thus positioned, itmay be seen that a rather crude ball and socket hinge is formed betweenthe frames 21 and 22 with the socket formed by the straight sides of theboxes 34 such that rearward, upward and straight lateral movement oflower frame 22 relative to upper frame 21 is prohibited but othermovements of frame 22 are freely permitted. This simulates the centricposition of the human mandible wherein rearward, upward and straightlateral movement of the lower jaw relative to the skull is prohibitedand therefore is the only position which is statically reproducible.

An incisal pin guide 44 is mounted on the front end of upper frame 21remote from angle guide 33. Incisal pin guide 44 is adjustable in lengthand serves the same well known functions of incisal pin guides of otherdental articulators. One of such functions is separating frames 21 and22 by the appropriate distance to correspond to the separation betweenthe patients upper and lower jaws. The length of incisal pin guide 44 isadjusted to engage a guide socket 45 mounted on frame 22 while thearticulator 20 is positioned on the plate 19 with the face bow and castmodel 16 in place as shown in FIGURE 2.

The next step in the use of articulator 20 is to mount the cast model 16of the upper jaw in the upper frame 21. A plate 38 may be provided andhave a threaded hole (not shown) for receiving the threaded thumb screw40 passing through frame 21. Mating holes and pins (both not shown) maybe provided on the plate 38 and frame 21, respectively, for preventingrelative movement therebetween upon tightening of screw 40. The castmodel 16 is supported in the impression 41 which is in turn sup portedon the support rod 11 of the face bow 10. For convenience the weight ofcast model 16 and impression 41 may be supported on the lower frame 22by means of a pair of wedges 42 appropriately adjusted to engage theunderside of impression 41. Incisal guide pin 44 is adjusted so that thehinge position of upper frame 21 is either touching pointer or is set ata recordable distance from pointer 15. The instrument might be providedwith a swinging arm, the bottom of which would be the same verticaldistance from frame 21 as center of pin 30 is from frame 21. The castmodel 16 is then secured to plate 38 by any convenient means such as aquantity of hard setting plaster 43 appropriately filling the spacebetween the cast model and the plate. It is to be noted that the uppercast model 16 is now mounted in the articulator in appropriate spatialrelationship and distance with respect to the ball and socket jointformed by condyles 29 and boxes 34. Any of several other known methodsof orienting the upper model may be used without departing from thisinvention.

The articulator 20 is then inverted and the cast model 17 of the lowerjaw is mounted on the cast model 16 with a check bite 46 positionedtherebetween to assure proper location, as shown in FIGURE 3. Check bite46 is made in any convenient manner well known to those skilled in theart. A plate 47 is mounted on the frame 22 by means of a threaded thumbscrew 49 passing through a hole in frame 22 into a threaded hole inplate 47. Mating holes and pins (both not shown) may be provided inplate 47 and frame 22 for maintaining orientation. The cast model 17 ofthe lower jaw is then secured to the plate 47 by any convenient meanssuch as filling the space therebetween with a quantity of hard settingplaster 50.

Referring now to FIGURE 5, a chew-in impression is made of theparticular individuals jaw movement. A plate 51 is made to fit the teethor gums of the upper jaw of the individual and four metal studs 52 aremounted in spaced relationship in the plate 51. The studs 52 arepreferably of a square or triangular cross-section having sharp cornerswith one of such corners facing forward when the plate is mounted in theindividuals mouth. The studs 52 protrude a short distance from thesurface of plate 51, generaly less than A3". A lower plate 53 is made tofit the teeth or gums of the lower jaw of the individual and the uppersurface may be covered with a layer of impression compound if desired.The surfaces of plates 51 and 53 may be of any convenient mating shapebut preferably are relatively spherical approximating the surface of an8" diameter sphere with the surface of plate 51 being convex and thesurface of plate 53 being concave. With the plates 51 and 53 mounted inthe individuals mouth, the individual closes his mouth so that studs 52engage the surface of plate 53 and the individual 53 causes the studs 52to scribe paths 54 in the surface of plate 53. By using the impressioncompound heretofore mentioned these paths may be made more easily. Theplates 51 and 53 are then removed from the individuals mouth and if animpression compound has been used on the surface of plate 53, a hardplastic reproduction is made of this plate. Plates 51 and 53 are thenmounted in the cast models 16 and 17, respectively, of the upper andlower jaws of the individual as shown in FIGURE 5; these models 16 and17 having been mounted in frame 21 and 22, respectively, which are notshown in FIGURE 5. When the studs 52 are positioned in the front corners55 of the path 54 the lower jaw is in what is commonly known as thecentric position i.e., where the lower jaw is in the most retrudedposition. By positioning studs 52 in corners 55 the proper positioningof lower cast model 17 may be checked and adjusted since this positionwill be represented by each of the condyles 29 engaging all three sidesof each of the open boxes 34.

A check which may be performed is by removing frame 21 and using acompass or pair of dividers with one point held on one condyle 29 andstriking an are adjacent the paths 54 beginning at the forward corner 55of each. Although paths 54 are shown as relatively square and regularthese paths will be irregular and different sizes and shapes fordifferent individuals. The two forward sides 60 of the paths 54 aregenerally arcuate and if the positioning of condyle posts 25 arecorrect, the arc struck by the compass or divider will coincide withthese sides 60. If the arcs 60 gradually lengthen it indicates greaterBennet movement or side shift of the mandible. As the one condyle movesforward the other may move outward and upward, outward and downward,outward and backward, or outward and forward.

The dental articulator 20 is then placed in an upright position withframe 21 above frame 22, and frame 21 is manually moved relative toframe 22 with studs 52 following the edges of paths 54. The condyles 29will obviously move relative to the associated open boxes 34 and iftracing the paths 54 by the studs 52 is limited by one or the other ofthe condyles 29 engaging one or more of the sides of the open boxes 34,such sides of the boxes 34 must be relieved such as by grinding. It isto be noted that the corners of the open boxes do not need relieving atthe three points of contact with the condyle 29 since this is thestarting position and has been adjusted to conform to the centricposition with the studs 52 engaging the forward corners 55 of the paths54. By providing open boxes 34 with appr0priately angled or relievedsides except at this centric position with the condyle 29 engaging allthree sides, it is apparent that this grinding step can be virtuallyeliminated.

The frame 21 is then lifted off the frame 22 and the boxes 34 arepartially filled with a soft formable material 56 such as a wax heatedto the appropriate temperature. The upper frame 21 is then replaced onthe lower frame 22 and manipulated to the centric position so thatcondyles 29 displace some of the material 56 to assume their position ofengaging the three sides of each box 34. The upper frame 21 is thenmanually moved with respectto frame 22 with the studs 52 following thepaths 54 formed in the lower plate 53. It may be seen that since thereare four studs 52 and four paths 54, and if interengagement between thestuds and paths is maintained the relative positions and movementbetween the upper frame 21 and the lower frame 22 is continuallymaintained even though the condyles 29 do not engage the sides of theopen boxes 34 nor does the incisal pin guide 44 engage the guide socket45. This relative movement causes the condyles 29 to form irregularpaths 57 in the material 56 by displacing and molding the material.Since the plates 51 and 53 are being manually moved in the identicalrelationship as they were moved by the individuals own jaw when theplates were mounted in the mouth, the paths 57 formed by the condyles 29are a replica and cooperate with condyles 29 in identical fashion to thecooperation between the ball and socket joints between the lower jaw andthe skull of that individual. These paths 57 are irregular and vary fromindividual to individual. Moreover, for any one individual the two paths57 on either side may be substantially different and not merely mirrorimages of each other.

The open boxes 34 may then be removed from frame 21 for convenience anda form die 58 made of each of the paths 57 and its relationship to thebox 34. Die 58 may be made in conventional fashion such as through theuse of dental stone and conforms to the path 57 as shown in FIGURE 7.After removal of die 58 the formable material 56 is removed from box 34and the box is then filled with a hard setting material 59 such asvarious types of cold cure plastics. Die 58 is then forced into material59 in appropriate orientation with respect to box 34 and therebyreproduces path 57 in the material 59; the start of this step beingshown in FIG- URE 8. Conventional parting compounds may be used on thematerial 56 and die 58 in the heretofore described steps.

After the material 59 has hardened the die 58 may be removed and theboxes 34 reinstalled in the guide 33 in their appropriate locations. Thehard plastic plate 53 may then be replaced by the original softimpression compound plate 53 in which were formed the paths 54 and theappropriate positioning of the lower cast model 17 may be remounted withplaster. Models 'with natural posterior teeth should be remounted with anew check bite.

The plates 51 and 53 may be then removed and the articulator 20 with theproperly mounted cast models 16 and 17 is essentially shown by FIGURE 4.Incisal pin guide 44 is then adjusted to the desired length and acontoured socket 61 may be formed in the guide socket 45 to give thedesired mouth opening and bite characteristics as is well known to thoseskilled in the art. With these adjustments made the desired dentures,bridges, caps, etc. may be constructed on the cast models 16 and 17 andthis work is facilitated by the fact that frame 21 can be easily liftedoff and replaced on frame 22 for accomplishing detailed work on eitherof the cast models 16 or 17. If it is desirable or necessary to use thearticulator 20 for constructing dentures, etc. for a different person,the cast models 16 and 17 may be removed by merely removing wing nuts 40and 49, open boxes 34 may be removed by removing wing nuts 37, socketguide 45 can be removed (means not being shown), and the positions ofeach of these and the positions of condyle posts 25 and incisal pinguide 44 may be recorded so that each may subsequently be replaced forcontinued work thereon.

Thus, it may be seen that a dental articulator and method are providedwhich are relatively easy to use and yet the actual jaw movements of anyindividual are more accurately reproduced. Further, the articulator isrelatively inexpensive to construct and the materials and additionalequipment needed are presently used and available to most dentists.

Having fully described my invention it is to be understood that I do notwish to be limited to the details herein set forth or to the detailsillustrated in the drawings, but my invention is of the full scope ofthe appended claims.

I claim:

1. A dental articulator for reproducing the movements of a human jaw,comprising: a lower frame and an upper frame for simulating the lowerand upper human jaws respectively, said frames having forward andrearward portions, a pair of condyle means movably mounted on therearward portion of said lower frame, a pair of open 'boxes movablymounted on the rearward portion of said upper frame, said open boxespositioned on said upper frame for fitting over said condyle means, eachsaid open box having an abutment corner portion with abutment wall meansengaging and mating with the associated said condyle means in a centricposition and preventing movement of that condyle means relative to thatopen box in the direction upward toward that open box and the directioninward toward the other said open box and the direction rearward of saidupper frame while permitting relative movement in all other directionsfrom said centric position, means for supporting the forward portions ofsaid upper and lower frames relative to each other, a formable materialin each of said open boxes, and means mounted on said upper and lowerframes to permit a confined relative movement between said frames tocause said condyle means to form a path within said formable materialwhereby subsequent relative movement following said path reproduces themovement of the jaw.

2. A dental articulator for reproducing the movements of a human jaw,comprising: a lower frame and an upper frame, for simulating the lowerand upper human jaws respectively, said frames having forward andrearward portions, a pair of condyle means mounted on the rearwardportion of said lower frame and extending upwardly toward said upperframe, a pair of open boxes mounted on the rearward portion of saidupper frame, said open boxes being open downwardly for fitting over saidcondyle means and supporting said upper frame on said condyle means,each said open box having an abutment corner portion with abutment wallmeans engaging and mating with the associated said condyle means in acentric position and preventing movement of that condyle means relativeto that open box in the direction upward toward that open box and thedirection inward toward the other said open box and the directionrearward of said upper frame while permitting relative movement in allother directions from said centric position, means for supporting theforward portions of said upper and lower frames relative to each other,a formable material in each of said open boxes, and means mounted onsaid upper and lower frames to permit a confined movement of said upperframe relative to said lower frame for moving said condyle means withinsaid open boxes to form a path within said formable material foraccurately reproducing that confined movement and related jaw movementsupon manipulation of said upper frame relative to said lower framesolely by said condyle means following said path.

3. A dental articulator for reproducing the movements of a human jaw,comprising: a lower frame and an upper frame for simulating the lowerand upper human jaws respectively, said frames having forward andrearward portions, a pair of condyle posts movably mounted on therearward portion of said lower frame for movement toward and away fromeach other, each said condyle post extending upwardly and having aspherical condyle at the upper end, a pair of open boxes movably mountedon the rearward portion of said upper frame for fitting over saidspherical condyles and supporting said upper frame on said condyleposts, each said open box having an abutment corner portion withabutment wall means engaging and mating with the associated saidspherical condoyle in a centric position and preventing movement of thatspherical condoyle relative to that open box in the direction upwardtoward that open box and the direction inward toward the other said openbox and the direction rearward of said upper frame while permittingrelative movement in all other directions from said centric position,means for supporting the forward portions of said upper and lower framesrelative to each other, a formable material in each of said open boxes,and means mounted on said upper and lower frames to permit a confinedmovement of said upper frame relative to said lower frame for movingsaid spherical condyles within said open boxes to form a path withinsaid formable material for ac cur t y r producing that confined movementand related jaw movements upon manipulation of said upper frame relativeto said lower frame solely by said spherical condyles following saidpaths.

4. A dental articulator for reproducing the movements of a human jaw,comprising: a lower frame and an upper frame for simulating the lowerand upper human jaws respectively, said frames having forward andrearward portions, cast models of the upper and lower human jaws, meansfor mounting said cast models on said upper and lower frames,respectively, a pair of condyle posts movaly mounted on the rearwardportion of said lower frame for movement toward and away from eachother, each said condyle post extending upwardly and having a sphericalcondyle at the upper end, a pair of open boxes movably mounted on therearward portion of said upper frame for movement toward and away fromeach other, said open boxes positioned on said upper frame for fittingover said spherical condyles and supporting said upper frame on saidcondyle posts, each said open box having an abutment corner portion withabutment wall means engaging and mating with the associated saidspherical condyle in a centric position and preventing movement of thatspherical condyle relative to that open box in the direction upwardtoward that open box and the direction inward toward the other said openbox and the direction rearward of said upper frame while permittingrelative movement in all other directions from said centric position, anincisal pin guide mounted on said upper frame remote from said openboxes for engaging said lower frame to separate said frames, a formablematerial in each of said open boxes, and means mounted on said castmodels of the upper and lower human jaw to permit a confined movement ofsaid upper frame relative to said lower frame for moving said sphericalcondyles within said open boxes to form a path within said formablematerial for accurately reproducing that confined movement and relatedjaw movements upon manipulation of said upper frame relative to saidlower frame solely by said spherical condyles following said paths.

5. A dental articulator for reproducing the movements of a human jaw,comprising: a lower frame and an upper frame for simulating the lowerand upper human jaws respectively, said frames having forward andrearward portions, a pair of condyle posts movably mounted on therearward portion of said lower frame for movement toward and away fromeach other, each said condyle post extending upwardly and having aspherical condyle at the upper end, a pair of open boxes movably mountedon the rearward portion of said upper frame for movement toward and awayfrom each other, said open boxes positioned on said upper frame forfitting over said spherical condyles and supporting said upper frame onsaid condyle posts, each said open box having an abutment corner portionwith abutment wall means engaging and mating with the associated saidspherical condyle in a centric position and preventing movement of thatspherical condyle relative to that open box in the direction upwardtoward that open box and the direction inward toward the other said openbox and the direction rearward of said upper frame while permittingrelative movement in all other directions from said centric position,means for supporting the forward portions of said upper and lower framesrelative to each other, means mounted on said upper and lower frames topermit a confined movement of said upper frame relative to said lowerframe for moving said spherical condyles within said open boxes, and ahard material in each of said open boxes having paths formed therein corresponding to that confined movement for reproducing the jaw movementsupon manipulation of said upper frame.

6. A dental articulator for reproducing the movements of a human jaw,comprising: a lower frame and an upper frame for simulating the lowerand upper human jaws respectively, said frames having forward andrearward portions, a pair of condyle posts movably mounted on therearward portion of said lower frame for movement toward and away fromeach other, each said condyle post extending upwardly and having aspherical condyle at the upper end, a pointed pin extending radiallyoutwardly from each spherical condyle a preselected distanceapproximating the human skin-to-condyle distance, a pair of open boxesmovably mounted on the rearward portion of said upper frame for fittingover said spherical condyles and supporting said upper frame on saidcondyle posts, each said open box having an abutment corner portioncomprising abutment wall means engaging and mating with the associatedsaid spherical condyle in a centric position and preventing movement ofthat spherical condyle relative to that open box in the direction upwardtoward that open box and the direction inward toward the other said openbox and the direction rearward of said upper frame while permittingrelative movement in all other directions from said centric position, aformable material in each of said open boxes, means for supporting theforward portions of said upper and lower frames relative to each other,and means mounted on said upper and lower frames to permit a confinedmovement of said upper frame relative to said lower frame for movingsaid spherical condyles within said open boxes to form a path withinsaid formable material for accurately reproducing that confined movementand related jaw movements upon manipulation of said upper frame relativeto said lower frame solely by said spherical condyles following saidpaths.

References Cited by the Examiner UNITED STATES PATENTS 1,622,9l0 3/27Homer 32-32 1,670,311 5/28 Musante 32-32 2,754,589 7/56 Highkin 32-322,816,360 12/57 Stuart 32-32 3,052,030 9/62 Spence -2 32-32 FOREIGNPATENTS 433,164 8/26 Germany. 544,125 2/ 32 Germany.

RICHARD A. GAUDET, Primary Examiner.

1. A DENTAL ARTICULATOR FOR REPRODUCING THE MOVEMENTS OF A HUMAN JAW,COMPRISING: A LOWER FRAME AND AN UPPER FRAME FOR SIMULATING THE LOWERAND UPPER HUMAN JAWS RESPECTIVELY, SAID FRAMES HAVING FORWARD ANDREARWARD PORTIONS, A PAIR OF CONDYLE MEANS MOVABLY MOUNTED ON THEREARWARD PORTION OF SAID LOWER FRAME, A PAIR OF OPEN BOXES MOVABLYMOUNTED ON THE REARWARD PORTION OF SAID UPPER FRAME, SAID OPEN BOXESPOSITIONED ON SAID UPPER FRAME FOR FITTING OVER SAID CONDYLE MEANS, EACHSAID OPEN BOX HAVING AN ABUTMENT CORNER PORTION WITH ABUTMENT WALL MEANSENGAGING AND MATING WITH THE ASSOCIATED SAID CONDYLE MEANS IN A CENTRICPOSITION AND PREVENTING MOVEMENT OF THAT CONDYLE MEANS RELATIVE TO THATOPEN BOX IN THE DIRECTION UPWARD TOWARD THE OPEN BOX AND THE DIRECTIONINWARD TOWARD THE OTHER SAID OPEN BOX AND THE DIRECTION REARWARD OF SAIDUPPER FRAME WHILE PERMITTING RELATIVE MOVEMENT IN ALL OTHER DIRECTIONSFROM SAID CENTRIC POSITION, MEANS FOR SUPPORTING THE FORWARD PORTIONS OFSAID UPPER AND LOWER FRAMES RELATIVE TO EACH OTHER, A FORMABLE MATERIALIN EACH OF SAID OPEN BOXES, AND MEANS MOUNTED ON SAID UPPER AND LOWERFRAMES TO PERMIT A CONFINED RELATIVE MOVEMENT BETWEEN SAID FRAMES TOCAUSE SAID CONDYLE MEANS TO FORM A PATH WITHIN SAID FORMABLE MATERIALWHEREBY SUBSEQUENT RELATIVE MOVEMENT FOLLOWING SAID PATH REPRODUCES THEMOVEMENT OF THE JAW.